Post-qualification application (PQA) is an idea that has been around for many years but seemed to have had its best chance of being implemented in 2004 when Prof Steven Schwartz made it a central recommendation of his report on fair access to higher education.

His proposal that A-levels be taken earlier and the first term of university put back to January was initially accepted by government but then lost in the fog of the general election the following year.

The UCAS bid to put PQA back on the agenda came in a presentation from chief executive Mary Curnock Cook in a private gathering of vice-chancellors. It was allegedly greeted by sources close to David Willetts with "real interest". But my prediction is that PQA will not be implemented – not in my professional life time at least.

Chatting to a senior figure at the Department for Education a couple of days ago, I asked what they thought the chances of the policy being introduced would be. With the studied neutrality of a professional assassin they dispatched the idea in three neat thrusts. First, the teaching unions would not accept earlier A-levels, especially as the revised UCAS proposal doesn't suggest that universities compromise by delaying the start of their first term. Second, shortening the time for teaching A-levels runs counter to Michael Gove's determination to introduce more rigour to the exam. Third, and most deadly, the benefits of post-qualification application are not great enough to make it worth ministers expending political capital to push it through. I put this last point to a contact who works at BIS and they ruefully agreed. "Just look at the numbers," they said, "around 3,000 applicants who could benefit by going to more prestigious universities against the disruption for getting on for half-a-million applicants, half-a-million school teachers and hundreds of thousands of academics and staff in HE, and it would cost millions to implement".

The rationale for PQA is that teachers tend to underestimate the grades of some of their pupils from disadvantaged homes. They end up accepting places at less prestigious universities on the basis of low predicted grades. By the end of August when they are clutching their string of As and Bs, all the places on the most competitive courses are already gone. The Sutton Trust reckons that each year several thousand pupils unjustly miss out on places at Russell Group institutions as a result of this.

But the notion that PQA would be good for widening access is not unchallenged. Back in 2004, admissions tutors argued that offering places only on the basis of grades already known would squeeze out the consideration of "soft" information that they use to admit bright students from poor backgrounds because of their potential rather than academic performance.

I have my own doubts about the effect that a shorter teaching year would have on the performance of students in state schools, which are already struggling to keep pace with an independent sector entirely dedicated to the mass production of top grades.